Radiant heating system



E. M. HARTER RADIANT HEATING SYSTEM Nov. 22, 1949 4 Filed, July 17, 19475 Sheets-Sheet 1 TIM I? klli IJYI swam tom Bison M.- Harier.

Nov. 22, 1949 HARTER 2,489,130

RADIANT HEATING SYSTEM Filed July 17, 1947 Y 5 Sheets-Sheet 12 l I l lElsan Bari/e1? Nov. 22, 1949 E. M. HARTER RADIANT HEATING SYSTEM FiledJuly 17, 1947 3 Sheets-Sheet 3 Patented Nov. 1949 UNITED STATES PATENTOFFICE 9 Claims.

The present invention relates to the heating of buildings, for exampleresidential structures, by means of radiant heat.

An object of the invention is to provide a building structure and aself-contained radiant heating system for affording selected temperatureconditions within closely controlled limits throughout the severalseasons.

Another object of the invention is to provide a building structure witha heating system which provides practically uniform radiant heat to thefloor or ceiling, or both floor and ceiling, of any or all rooms orapartments in a single or multistor'ied building.

Still another object of the invention is to provide a building structurewith a radiant heating system that is quickly and effectively responsiveto heat demands and which is arranged to effectively cut oil delivery ofradiant heat to the rooms when required, to maintain a desired roomtemperature and prevent the personal discomforts of heat over-runs inmild weather.

A further object of the invention is to provide an improved wall-to-wallradiantheating system for buildings and an arrangement of buildingconstruction elements cooperating therewith to render it efficient andeconomical in operation, and relatively simple and inexpensive toconstruct.

A still further object is to provide means for accomplishing theaforementioned objects automatically and without waste of space withinthe building.

These and other objects are attained by the means described herein andexemplified in the accompanying drawings in which:

Fig. 1 is a horizontal fragmental sectional view of a building structureembodying a radiant heating system of the invention, parts being brokenaway.

Fig. 2 is a cross-sectional view taken on line 2-2 of Fig. i.

Fig. 3 is a cross-sectional view taken on line 3-3 of Fig. 1.

Fig. 4 is a cross-sectional view taken on line 4-4 of Fig. 1.

Fig. 5 is a cross-sectional view taken on line 5-5 of Fig. 1.

Fig. 6 is a wiring diagram for the automatic control of the system ofthe invention.

The use of non-luminous radiant heat for heating buildings is known inmany forms amongst which are found various arrangements of sinuouslydisposed steam or hot water pipes embedded in east cementitious floorsand/or wall slabs. Objections to the latter arrangement are chieflythose of retarded delivery of radiant heat to the rooms when the systemand building structure are cold, and the inability to retard the demandin the milder seasons of the year. Moreover, these systems make noprovisions for supplying fresh air to the occupants, so that fresh airis sometimes lacking and at other times is supplied at the expense ofcomfortable room temperature. The embedded pipe systems are oftenpractically unsatisfactory because of lack of uniformity of heatdistribution due to long pipes and the location thereof.

The embodiment of the invention herein illustrated contemplates, inaddition to its effectiveness, the building of the heating system into ahouse during construction but the broader aspects of the invention willnot preclude the addition of such a system to an existing constructionunder certain circumstances.

Fig. 1 shows, by way of example, a building structure It havinglongitudinal side Walls II and I2, and end walls I3, all of thewell-known brick and cinder block construction.

Each of the side walls II and I2 has a longitudinal channel, l4 formedtherein at each floor level resulting from the omission of the requisitenumber of courses of the blocks I5.

Metal joists I6 of special end construction are entered endwise intochannels I4 at suitable intervals along said channels.

The ends of joists 16 are constructed to provide support for the end ofthe joist on the bottom horizontal side wall of the channel I4 withoutappreciably obstructing the longitudinal continuity of said channel I4,so that the said channel may form, in the finished building structure, apart of a combined air duct and pipe receiving duct, indicated generallyat i1, located between the levels of a given floor l8 and the ceiling l9below it and disposed partly within and partly outside the body of thesupporting building side wall II or I2. (See Figs. 2 and 3.) .loists I6may be formed of top and bottom chords w and 2|, each chord comprising apair of angle irons, 22, secured to suitably constituted web formingmembers 23.

As can best be seen in Fig. 3, the bottom chord ti of each joist i6 isinterrupted to form an opening 24 therein near each end so thata hotWater supply pipe 25 may be moved into and from the duct I'l along wallII and a hot water return pipe 26 may be similarly accommodated in theremaining duct i1 alongside wall I2. There are suitable truss rods orbars 21 arranged in a generally inverted V-formation between the topchord 20 and the portions of chord 2| on opposite sides of opening 24,the aforementioned pipes passing between said bars 21, and are thusdisposed accessibly between the top and bottom levels of the joists. Thecut-out portion forming the opening 24 at each end of each joist allowscontinued radiation after satisfying a small heat the pipes to lierelatively close to the ceiling 3 level without interference with theangle members 22 of the bottom chord 2 I p The grooves i4 in thebuilding sidewalls are iesirably lined on the bottom and vertical faces.

with an air impervious sheet 23 to minimize air pressure losses throughthe masonry work of the sidewalls.

Plates 23 extend between adjacent sides of adjacent joists it inuniformly spaced parallelism with the building sidewalls so that theycollectively serve to define one side of each duct H. A longitudinallyextending arched sheet or pan 30 rests on or is inserted between theadjacent joists and the plates, and serves initially as a form forreceiving a poured concrete sub-floor slab 3| which has a flat topsurface 32 disposed appreciably below the top of the joists. The bottomface assumes the contour of the series of arched sheets 30 below whichare inverted arched air channels 33 that are closed on the bottom by theceiling sheets 34 which are fastened to the bottoms of the joists.

Floor paving slabs It on tops of the joists form the top of air channels38 above slab 3|. The plates 23 are provided with holes 31 above the toplevel of slab 3| and holes 38 beneath the arched sheets 30. Radiantheating pipes 39 and 40 pass through the channels 33 and 33 and aresuitably connected at one end with hot water supply pipe 26, and at theother end with hot water return pipe 26. The plates 29 have narrow slots44 affording opportunity for air flow therethrough only under conditionsof air pressure differential between the ducts H on opposite sides ofthe building. The channels 33 and 36 are thus normally air locked untilforced air circulation is set up through them. Under this normally airlocked condition heat-from pipes 39 and 40 may pass directly to floorpaving l8 and ceiling I! by radiation without the necessity of firstheating the concrete mass of interiloor slab 3| to a degree at which itwill begin to give ofl. radiant heat. The sensible heat is thus speedilyradiated to the rooms and with greater economy than in the knownarrangement of embedded heating pipes within a concrete floor slab.

When room temperature requirements are satisfied and the flow of hotwater is arrested in the pipes, the heat of the fluid at rest thereincontinues to radiate and compensate for heat losses from the rooms for atime depending on the rate of that loss from the building.

When the building heat loss is very low, as in moderate weather, and theaforesaid continued radiation is undesired in the rooms, that heat iscarried away by setting up a directional air fiow in the normallyair-locked spaces wherein the pipes 25, 39, 40 and 23 are housed. Themeans for eifecting th heat removal may include air cooling and airhumidifying apparatus 4| of the motor driven blower or fan type, andhaving a supply duct 42 for cooled and humidified air leading from it tothe duct H at the right hand side of Figs. 1. 2 and 3 and wherein thehot water supply pipe 25 is housed. The remaining duct H at the lefthand side of said figures, and which duct houses hot water return pipe26, has a return air duct 43 connecting itwith air conditioner 4|. Aconduit 430 connects with return duct 43 and with the atmosphere outsidethe building, therefore providing for the introduction of outside airinto the air which is circulated by apparatus 4|, as rearranged and inknown manner in the art. The restricted slots 44 in plates 23, whichcollectively form one longitudinal sideplant such as 43. Conductor wallfor each of ducts i1, serve to provide entry of the cool air from oneduct l1 along pipes 33 and 43, on the one side and return the air withthe heat from said pipes back into the opposite duct l1 and from thenceto the air conditioner 4|.

The conditioned air supply is available to provide fresh air in therooms 43 by a suitable pipe 43 in the wallil. is adapted to be opened asrequired by suitable means on demand for fresh room air independently ofheat demand. Pipe II is in constant communication with the duct H at theright of Fig. 3.

The exit of stale room air may be by way of a pressure opening louveredexit 43 which is actuated by the; pressurewcreated in the room by theincoming pressure supply of conditioned air from pipe 46 when valve 41is open. I

It will be understood that the hot water (or steam) supply is of theforced circulation variety from a suitably fired heating plant 43 fromwhich pipe 30 carries the heating medium (steam or water) tofsupply pipe23 from whence it is carried via pipes 39 and 43 to-return pipe 23. Pipe23 connects with the boiler by means of pipe 51.

The heating plant 49 and the air conditioning plant 4| are desirablysubject to automatic control, but may be otherwise suitably controlledin any fashion known in the art.

Fig. 6 shows an electrical wiring diagram of means for automaticallycontrolling the tempera ture in the building and the air supply as suchor as a control against heat over runs, or both.

A hygrometrically actuated electrical control device 52 and a high-lowtemperature thermostat 53 are both mounted conveniently in the interiorof the building in the present embodiment of the invention. The housecurrent lines 54 and 53 supply volt A. C. current for the motors 38 and51 of the air conditioner 4| and heating plant 43 respectively, and fora stepdown transformer that provides electrical energy for low voltagecircuits to actuate the solenoids 58.33, 63 and 6|.

Conductor line 34. has connected thereto one terminal 32 of transformerprimary winding 33, one terminal 64 of motor 33, one terminal 65 ofmotor 51 and one terminal 33 01' a master control panel 31 of theheating apparatus 51. The mas-l ter control panel 61 will be understoodto carry additional electric terminals (not shown) for connection inknown manner to the conventional electric safety and stand-by controls(not de tailed) forming a part of a conventional heating line 35connects with the terminal 33 of winding 83 of the transformer i3, andwith terminal 33 of normally open switch 10 that is operable by solenoid53. A conductor 1| connects terminal 12 of switch 13 with terminal 13 ofmotor 51. Conductor 14 connects conductor I3 permanently with terminal15 of master control panel 81. A conductor 23 forms an electricalconnection between conductor 55 and terminal 11 of a switch 13 which isclosed by solenoid 33. Terminal 13 of switch 13 is connected byconductor 34 to terminal 8| of motor.

The low voltage control circuits are arranged so that conditioned airmay be caused to circulate into and out of the rooms to afford healthfulatmosphere for the occupants according to hygrometric settings oninstrument 3!, or such air may be caused to circulate as a heat removingmedium passing under the floor and over the celling. In the diagram(Fig. 6), low voltage con- A suitably controlled valve 41 ductorsxfand88 are connected to opposite ends of secondary winding 84 of transformer58. Conductor 82 is electrically connected to fixed contact 85 ofhygrometrlcally controlled circuit closing instrument 52, and aconductor 86 connects conductor 82 with the moving contact terminal 81or the high-low room thermostat 53. Conductor 83 is connected to one endof solenoid 58 by a wire 88 and said conductor 83 also connects with oneend of solenoid 59. The remaining end of solenoid 59 is connected to thelow" terminal 89 of thermostat 53 by conductor 98. The remaining end ofsolenoid 58 is connected by wire 9| to one end of solenoid 88, while theremaining end of said solenoid 68 is connected by conductor 92 to thehigh" terminal 93 of thermostat-53. A conductor 94 is electricallyconnected intermediate the ends of wire 9| and to one end of solenoid6|. The remaining end of solenoid 6| is connected to a conductor 95which connects with terminal 96 of the moving contact 91 of instrument52.

It will be noted that when a demand for humidified or otherwiseconditioned air in the rooms of the building causes closing of thecircuit in the instrument 52 solenoids 6| and 58 will be energizedsimultaneously so that air louver or valve 41 will open allowing thepressure of air in pipe 46 to introduce fresh or conditioned air intothe room, as and so long as solenoid holds switch 18 closed forcompleting a power circuit including blower motor 56 of airconditionerapparatus 4| and said apparatus delivers air through airsupply duct 42 into duct H at the right hand side of Fig. 3 which feedsthe pipe 46. The stale air is exhausted to the outside of the buildingby Way of opening 48 as the louvers 488 swing outwardly from a normallyclosed position by the force of increased pressure inside the room.

The radiant heating system is normally inoperative when the movingcontact arm 538 is disposed out of contact with the low" or heat demandterminal 89 of the thermostat 53. Upon demand for more heat in therooms, arm 538 makes an electrical connection between terminals 81 and89 and a closed circuit is established to energize solenoid 59 fromsecondary transformer winding 84, through conductor 83 to solenoid 59andfrom solenoid 59 to terminal 89, through arm 538'to terminal 81 andthence by way of conductor 86 to conductor 82 back to secondary winding84 of the transformer. When solenoid 59 is energized it closes switch 18and a power circuit is completed to include the water pump motor 51 ofheating apparatus 49 and hot water is forced through pipe 58 into pipe25 and from it through each of the pipes 39 and 48 which empty intoreturn pipe 26 and from it through pipe 5| to the boiler (not detailed)in the heating apparatus 49.

The power circuit to hot water pump motor includes power conductor 54which connects with motor terminal 65 of motor 51 through the winding ofsaid motor to terminal 13, thence through conductor 1| to terminal 12,through switch 18 to terminal 69 and returning through power conductor55.

The power circuit,for blower motor 56 is established from conductor 54,to terminal 64, through the winding of motor 56 to its terminal 8|thence through conductor 88, terminal 79, switch 18 and terminal 11 toconductor 16 which connects with conductor 55.

As can be best seen in Figs. 2 and 6, a normally closed damper or valve88 is provided in return air pipe 48 and this is adapted to be opened bysolenoid 68 whenever the thermostat arm 538 contacts the high" terminal93. At that time solenoids 58 and 68 are energized in series in acircuit including conductors 83, 88, 9|, :92 to terminal 93 andreturning through arm 538, terminal 81 and conductors 88 and 82. It willbe noted when valve 98 is opened the pressure air flow set up by airconditioning apparatus passes through the air duct 42 to the right handside of the building and is distributed throughout the length of duct llwhich carries water pipe 25. The air passes through the several slots 44along the pipes 39 and 48 and out of the corresponding slots 44 at theopposite side of the building into the duct ll on the last mentionedside of the building, and flows through return air pipe 43, past theopen valve 98 and back to the air conditioner 4|.

Should there be a demand for fresh room air during this operation, thesolenoid 6| would also be actuated to operate valve 41 so that thesupply of fresh conditioned air would flow at a lesser rate over theceiling and under the floor and also through pipe 46 into the room. Uponsatisfaction of the fresh air demand the instrument 52 would break thecircuit to solenoid 6|, permitting valve 41 to close while valve 98remains open and motor 56 continues to force the air as a cooling mediumfor pipes 39 and 48 until arm 538 of thermostat breaks contact withcontact terminal 93.

It is to he noted that ease of assembly of the heating Water (or steam)circuit pipes is afforded by providing the openings or breaks 24 in thebottom chords 2| of the joists. The openings occur closely adjacent theinside face of the building side walls, and the pipes 25 and 26 aretemporarily supported accessibly below the joists and the pipes 48 thenconnected to them, Whereupon the assembled pipes 25, 26 and 48 may beraised into the openings 24 and into the arched spaces between thejoists. Thereafter longitudinal plates 99 are suitably securedtransversely across all chords 2| on opposite sides of the openlugs 24therein. If the ceiling be in a dwelling apartment the plaster coatingmay be applied over plates 99 and the ceiling sheets I9 in order topresent an even and uninterrupted finished ceiling. Where the decorativeappearance of the ceiling is secondary, the plates 89 and theirfastenings (not shown) may remain exposed. Suitable metal re-enforcingrods, bars or mesh I88 may be employed in the cast interfioor slab 8| inany suitable fashion to provide additional strength.

Angle irons |8| are disposed transversely across the top chords 28 ofthe joists, and the course of back-up or cinder blocks l5, which definesthe top of the groove I! in each building wall, is sup- [ported thereon.

In the winter season the air from apparatus 4|, which is delivered ondemand to the rooms via .duct 42, the duct I! at the right-hand side ofFig. 1 and the pipes 48, ma be tempered by the heat of pipe 25 as itpasses through the said duct H and over the said pipe 25 therein anddischarges through one or more of the pipes such as 46. When there is asimultaneous high temperature condition in the inter-floor space and ademand 'for a change of room air, the room air is provided lpartly atthe expense of the air flow through the channels housing the heatingpipes 39 and 48. The efiect however is that of replacing the warmerstale air in the room with eooler comfortable. The fresh air demand isusually satisfied in a comparatively short time, after which all of thecirculating air volume is directed along pipes 38 and 40 to carry awayunwanted heat as required.

The heating plant will be understood to be of the type commonly referredto as automatic and the details of its controls for maintaining asuitable supply of available hot water (or steam) form no part of theinvention herein. The air conditioning apparatus may be or selectedtypes to humidify, de-humidify and if desired cool the air by mechanicalrefrigeration seasonally and the details of its operation, beyondsupplying conditioned room air and/or heat removal air as aforementionedform no part of the present invention.

While the embodiment herein illustrated shows a single apartment havingone hot water (or steam) pipe 25 and one return pipe 26, it will beunderstood that the size and interior arrangemerit of the buildingstructure may require multiples or variants in the arrangement; of thesepipes.

Wh-atisclaimedis:

1. In a radiantly heated building structure having side walls, endwalls, a floor bounded by said walls, and a ceiling below the floor andcoextensive therewith, the combination of means intermediate said floorand ceiling arranged to provide a duct along each sidewall and form ashallow space between said ducts and below the floor, and anotherco-extensive shallow space in isolated relation to the first mentionedshallow space. immediately above the ceilin and intermediate the ducts,said spaces having restricted communication at opposite ends with saidducts, a hot water supply pipe housed in one of said ducts, andlongitudinally co-extensive therewith, a correspondingly disposed waterreturn pipe in the other of said ducts, a plurality of transverselyextending pipes passing through the spaces below the floor and above theceiling respectively and having their several opposite ends communicatinwith the hot water supply pipe and the water return pipe respectively,means including a source of hot water and a forced circulation meanstherefor for supplying hot water under pressure to the hot water supplypipe, and a. pipe so that the room atmosphere remains entirelyconnecting the water return pipe with the source of hot water supply.

2. A radiant heating system for a, building having sidewalls, a floorand a ceiling below said floor, said system comprising means providing apair of parallel ducts intermediate the floor and ceiling and along therespective sidewalls, means disposed horizontally between adjacent sidesof said ducts whereby a shallow horizontal space is provided immediatelybeneath the floor and an independent shallow space is providedimmediately above the ceiling, a series of pipes extending through eachof said shallow spaces and into the ducts, a hot water supply pipedisposed in one of said ducts and connected with the adjacent ends ofall of pipes of said series, a water returnpipe disposed in theremaining duct and having the remaining ends of the pipes of said seriesconnected therewith, means selectively providing forced circulation ofhot water through said pipes whereby radiant heat may be transmittedsubstantially unimpeded from the aforementioned pipes to the bottom ofthe floor and the top or the ceiling, a pressure air supply 9196',

connected to one or said ducts, a pressure air return pipe connectedwith the remaining duct, each or said ducts having a restrictedcommunication with the several shallow spaces immediately adjacent eachpipe of the series therein whereby said shallow spaces are normallsubstantially airlocked with relation to the respective ducts, and meansfor setting up i'orced air circulation in one of said ducts wherebypressure air is forced to flow along the series of pipes in the shallowspaces and into the remain nl duct for exit therefrom through the airreturn Pip 3. In a radiant heating system, the combination with abuilding structure having sidewalls, joists traversing the spacesbetween said sidewalls. and a fioor and a ceiling connected respectivelyto the top and bottom respectively of the joists, of an inter floorslabtraversing the joists and terminating at opposite edges in spacedparallelism with the sidewalls at a distance from opposite ends of thejoists, the opposite ends 01' the joists being substantially n betweenthe top and bottom chords thereof, whereby longitudinal ducts are formedbetween the said floor and celling along eachsidewall and separatetransverse channel spaces are formed between the ducts above and belowsaid interfioor slabs, a series of parallel radiant heating pipesextending from one duct to the other duct through the channel spaces. a.hot :water supply pipe disposed longitudinally within one of said ducts,a water return pipe disposed longitudinally within the other 01' saidducts, said radiant heating pipes each connected at is opposite ends tosaid supply and return pipes respectively, a source of hot water supply,means comprising a feed pipe'connected to said supply pipe, and aselectively operable pump for delivering hot water from the said sourceof supply under pressure into said supply pipe, a pipe connecting thereturn pipe to the said source oi supply, and thermostatically operatedmeans in the space between the sidewalls for controlling operation ofthe pump.

4. In a radiant heating system, the combination with a buildingstructure having sidewalls, joists traversing the spaces between saidsidewalls, and a floor and a ceiling connected respectively to the topand bottom respectively of the joists, of an interfioor slab traversingthe joists and terminating at opposite edges in spaced parallelism withthe sidewalls at a distance from opposite ends of the joists, theopposite ends of the joists being substantially open between the top andbottom chords thereof, whereby longitudinal ducts are formed between thesaid floor and celling along each sidewall and separate transversechannel spaces are formed between the ducts above and below saidinterfloor slab, a series of parallel radiant heating pipes extendingfrom one duct to the other duct through the channel spaces, a hot watersupply pipe disposed longitudinally within one of said ducts, a waterreturn" pipe disposed longitudinally within the other 01' the saidducts, said radiant heating pipes each connected at its opposite ends tosaid supply and return pipes respectively, a source of hot water supply,means comprisin a feed pipe connected to said supply pipe, and aselectively operable pump for delivering hot water from the said sourceof supply under pressure into said supply pipe, a pipe connecting thereturn pipe to the said source of supply, plates extending from thefloor to the ceiling and abutting the said opposite edges a,4sc,1so

of the said interi'ioor slab, and having openings aflording restrictedcommunication between each duct and the opposite ends of the channelsclosely adjacent the radiant heating pipes, and means for selectivelyintroducing cooling air under pressure to one of said ducts for passagetherefrom through the restricted communicating openings in the severalchannels for cooling the radiant heating pipes in said channels andducts.

5. In a building having a substantially closed space between a floorthereof and the ceiling below it, the combination of means dividing saidspace into a pair of laterally spaced ducts and vertically spacedtransverse channels each having restricted communication at its endswith said pair of ducts, radiant heating pipes in the channels andhaving their ends extending into the ducts, supply and return pipesdisposed respectending ends of the radiant heating pipes, selectivelyoperable means to supply a circulating heating medium under pressure tosaid supply pipe for passage through the radiant heating pipes wherebythe floor and ceiling are heated, and selectively operable means toprovide forced circulation of cooling air over said pipes in the ductsand channels housing said pipes for simultaneously cooling the pipes andcurtailing the heating of the floor and ceiling.

6. In a building having sidewalls, a floor and a ceiling below saidfloor together defining a hollow interfloor space, the combination of asupply pipe and a return pipe in said space along opposed sidewalls,radiant heating pipes connected at opposite ends to said supply pipe andsaid return pipe, plates traversing the radiant heating pipes adjacentthe junctions of the latter and the said supply and return pipes wherebythe spaces around said supply and return pipes are substantiallyisolated from each other and the radiant heating Pipes, said plates eachhaving restricted apertures therethrough adjacent each radiant heatingpipe, means to selectively produce a forced circulation of a fluidheating medium through the supply pipe and the connecting radiantheating pipes to said return ipe, means to elect a forced circulation ofcooling air into the interfioor space between one building wall and theadjacent plates for movement through the restricted apertures along theradiant heating pipes, and thermostatically operating means controllingthe circulating means for the fluid heating medium and the cooling air.

tively in said ducts and connecting with the ex- 10 to the oppositeduct, a valve controlling discharge of cooling air from the lastmentioned duct whereby movement of air through the channel space ,may bearrested, a valve controlled conduit connectin the first mentioned ductand the space above the floor for directing pressure air into said spaceconcurrently with or independently of the air flow through the channelspace, and electrically operated, thermostatically controlled means forthe pressure air supply means and the heating fluid supply means.

8. In combination with a pair of opposed building sidewalls having afloor and ceiling below it 'to form a hollow space between said walls, aplate restricted apertures therethrough adjacent each radiant heatingpipe, means for providing a plenum pressure supply of cooling air to oneof said ducts and a valve for controlling discharge from the other ductto selectively control the flow of cooling air through the channels fromthe first mentioned duct to the last mentioned duct through saidrestricted apertures in the plate structures.

9. In combination a building having a floor, a

slab spaced below the floor to provide a traverse respect to said ducts,means to deliver cooling air under pressure to the remaining duct, avalve controlled air pipe connecting said remaining duct-with the spaceabove the door, a hot water supply pipe in said remaining duct, aradiant heating pipe connected to said supply pipe and extending throughthe channel and the plate structures at opposite ends thereof into thefirst 7. The combination with a pair of opposed building walls, a floorand a ceiling below said floor together forming a closed interfloorspace, of a supply pipe and a return pipe disposed in said space alongrelatively opposite sides thereof, plate members along each of saidpipes each forming a wall of a duct for the respectivepipes and providedwith restricted openings, the space between said walls of said ductsconstituting a transverse channel space in normally air-locked relationto said ducts, a plurality of substantially parallel radiant heatingpipes in the channel space having the opposite ends thereof passingthrough the respective duct walls adjacent the restricted openings andconnected to the said supp y and return pipes, means to suppl pressurefluid heating medium to said supply pipe and from it to the radiantheating'pipeswhereby the floor and ceiling are uniformly heated, meansto supply cooling air under pressure to one of said ducts for velocitytravel through the restricted openings and across said channel spacementioned duct, a hot water return pipe in the said first mentionedduct, means to selectively deliver hot water under pressure to saidsupply pipe, and an electrical control system for effecting joint andseveral operation of said valves and said air supply means at one timeand for eifecting simultaneous operation of said water supply means theair supply means and the val e controlling the air pipe which connectswith the space above the floor at another time.

ELBON M. HAR'I'ER.

REFERENCES CITED The following references are of record in the me ofthis patent:

Number Name Date 899,078 Salmon Sept. 29, 1908 1,995,481 Myers Mar. 26,1935 2,240,951 Hamjy May 8, 1941 2,392,240 Frankel Jan.'1. 19402,442,201 Elbsrty May 36, 1948

